NaviLog – the free sailing logbook app with an anchor alarm
For Android and iPhone. Logs your trips by GPS, stands anchor watch, marks a man overboard and warns of bad weather with your phone's own barometer – offline and without an account.
In short: NaviLog is a digital logbook for sailors, skippers and charter crews. The full logbook with GPS tracking, anchor alarm, MOB and barograph is free and ad-free. If you want PDF, GPX or CSV exports or a cloud backup, a single one-time purchase unlocks Pro – no subscription. Made in Switzerland by a sailor.
What the sailing logbook does
- Automatic trip logging: background GPS tracking with the screen off and no internet; distance in nautical miles, duration, average and top speed, sailing/motor/anchor markers, engine hours, notes, weather and crew.
- Anchor alarm with a real swing circle: computed from chain length, water depth, bow height and boat length, optionally tide, mooring type, a second anchor or a swing sector; pre-alarm, GPS-loss alarm and battery warning; adjustable while armed.
- Man overboard: one tap marks the position and guides you back with live bearing and distance.
- Barograph and storm alarm: pressure curve from 6 hours to 7 days from the phone's barometer, alarm on a significant fall such as 3 hPa in 3 hours – no signal needed.
- For skipper and crew: crew, skipper and yacht profiles, official crew lists, checklists, sea-miles certificates, OpenSeaMap seamarks and a red night-watch mode.
Free or Pro?
| Free | Pro (one-time) | |
|---|---|---|
| Logbook, GPS tracking, statistics | ✓ | ✓ |
| Anchor alarm, MOB, barograph, storm alarm | ✓ | ✓ |
| Seamarks, night mode | ✓ | ✓ |
| PDF logbook, sea-miles certificate | – | ✓ |
| GPX export (OpenCPN, plotters), CSV import/export | – | ✓ |
| Cloud backup, crew lists, templates, offline charts | – | ✓ |
| Ads / subscription | none | none |
The Pro price is shown in the App Store or Google Play for your country.
What to look for in a sailing logbook app
- Offline: there's often no signal at sea. Logging and alarms must not depend on a connection.
- A background anchor watch: an alarm the OS kills at 2 a.m. is worse than none. On Android the app must be allowed past battery optimisation; on iPhone it has to stay in the foreground.
- Your data stays yours: local storage, export to open formats (GPX, CSV, PDF), no forced account.
- Cost: subscription or one-time purchase? What stays free?
- Sea-miles proof: if you're collecting miles for a licence, you need a clean certificate.
NaviLog was built around exactly these points. The story behind it: The Best Sailing Logbook App Is the One That Works When Everything Else Doesn't. Every feature in detail: the complete guide. Straight answers: the FAQ.
Run a charter company or sailing school? NaviLog Fleet adds a digital check-in and handover to the same app.